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@kylefox
Created October 17, 2018 15:58
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Convert Base64 data URLs to File objects for Trix attachments
window.AttachmentUtils = (function() {
var BASE64_MARKER = ';base64,';
var Utils = {
// Takes a file size (in bytes) and returns a human-friendly string representation.
humanFileSize: function(size) {
if(size < 1) return "0 bytes";
// http://stackoverflow.com/a/20732091
var factor = 1000; // Technically it should be 1024, but looks like most apps use 1000...
var i = Math.floor( Math.log(size) / Math.log(factor) );
return ( size / Math.pow(factor, i) ).toFixed(1) * 1 + ' ' + ['B', 'kB', 'MB', 'GB', 'TB'][i];
},
// Does the given URL (string) look like a base64-encoded URL?
isDataURI: function(url) {
return url.split(BASE64_MARKER).length === 2;
},
// Converts a data URI string into a File object.
dataURItoFile: function(dataURI) {
if(!AttachmentUtils.isDataURI(dataURI)) { return false; }
// Format of a base64-encoded URL:
// data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAYAAAAEOCAIAAAAPH1dAAAAK
var mime = dataURI.split(BASE64_MARKER)[0].split(':')[1];
var filename = 'dataURI-file-' + (new Date()).getTime() + '.' + mime.split('/')[1];
var bytes = atob(dataURI.split(BASE64_MARKER)[1]);
var writer = new Uint8Array(new ArrayBuffer(bytes.length));
for (var i=0; i < bytes.length; i++) {
writer[i] = bytes.charCodeAt(i);
}
return new File([writer.buffer], filename, { type: mime });
}
};
return Utils;
})();
$(function() {
$(document).on('trix-attachment-add', function(event) {
var attachment = event.originalEvent.attachment,
url = attachment.getURL();
// Convert data URLs to File objects.
if(!attachment.file && AttachmentUtils.isDataURI(url)) {
attachment.file = AttachmentUtils.dataURItoFile(url);
}
if(attachment.file) {
return uploadAttachment(attachment);
} else {
console.error('Could not upload attachment.');
console.error(attachment);
attachment.remove();
}
});
});
@aproberts01
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Thank you for this! This solution was exactly what I was looking for.

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ghost commented Feb 26, 2020

Nice gist, but I am having errors at uploadAttachment() method, uploadAttachment is not defined. Where is this method at and what's inside it?

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